Mirror construction



i w. H. TAYLOR.

MIRROR CONSTRUCTION.

APPLICATIONFILED OCT. 6| 1921.

13,434,860o Patented Nov. 7, 1922.

Hill. 9

avmwra Patented Nov. 7, 1922.

NITE stares FATENT OFFICE.

WILLIAM'I-I. TAYLOR, OF FORD CITY, PENNSYLVANIA, ASSIGNOR TO PITTSBURGHPLATE GLASS CDMPANY, A CORPORATION OF PENNSYLVANIA.

MIRROR CONSTRUCTION.

Application filed October 6, 1921.

T0 (17? whom "it may concern:

Be it known that I, WILLIAM H. TAYLOR, a citizen of the United States,and a resident of Ford City, in the county of Armstrong and State ofPennsylvania, have made a new and useful invention in Improvements inMirror Constructions, of which the following is a specification.

The invention relates to mirror constructions and particularly thoseemploying a netting of metal or similar material at the back to protectthe silver or other coating and to add reinforcing strength tending tohold the structure together in case the glass is shattered. Theinvention is illustrated as applied to a parabolic mirror, such as areused in connection with search lights, but is not limited to such useand may be em ployed to advantage on any mirror employing the metallicprotecting backing. Heretofore it has been the practice to imbed thereinforcing netting in a coating or paste adherent to the back of theglass or the coating carried thereby, but with such construction theattachment to the glass is relatively weak, and the whole backing isliable to loosen from the glass at the edges and pull away. The objectof the invention is to provide improved means for posi tively anchoringthe metallic netting to the edge of the glass. One embodiment of theinvention, is illustrated in the accompanying drawings wherein:

Figure 1 is a section on an enlarged scale through the edge of aparabolic mirror in cluding the improvement, and Fig. 2 is a sectionthrough the glass plate before the application of the backing.

In constructing the mirror the glass 1 is first provided with a groove2, which, in the case of a glass seven-sixteenths inches thick, ispreferably about one-eighth inch wide and one-sixteenth inch deep. Thisgroove is formed by a grinding operation. The sheet is then provided onits. convex side with a silvering coating 3, over which is electroplateda copper coating 4. A. third coating 5, consists of several layers ofvarnish. Upon this backing thus prepared is placed the woven copperfabric 6, which may be generically designated as a flexible metal fabricas this metal protecting fabric might be made in a variety of waysalthough the woven copper mesh or screen Serial No. 505,894.

is the material which is at present universally used for this purpose.This fabric 6 is brought around the edge of the glass and over thegroove 2, after which the clamping or binding wire 7 is applied. Thiswire is preferably about a No. 20 gauge and of phosphor bronze, threeturns or laps being illustrated although a greater or less number ofturns and wires of varying size may be employed, depending uponconditions. The ends of the wires are preferably secured by beingsoldered to adjacent turns of the wire.

After the wire is secured in position, the copper fabric is bent aroundto cover the wire, as indicated at 8 in Fig. 2. A final coating is thenapplied to cover the metal fabric and give the mirror a finishedappearance. This covering, indicated by the reference numeral 9 in Fig.1, preferably consists of one or more coats of varnish thickened withzinc oxide, although various compositions might be employed for thispurpose. The construction as illustrated and described serves to holdthe backing very securely in place as the wire positively clamps theedge of the metal fabric in position .in the edge of the glass and thereis no danger of the backing coming off, such as is the case where theentire attachment of the backing depends upon the adhesion of thevarious coatings, including the adhesion of the silvering to the glass.In case the glass is accidentally shattered, the backing with its secureholding means tends to hold the pieces together so that the mirror iseifective to a certain extent at least until it can be replaced. Theadvantages of the construction incident to its security and the ease andcheapness with which it may be applied will be readily apparent to thoseskilled in the art. It will be understood that the invention is capableof embodiment in a wide variety of forms and that the one shown ismerely illustrative of the principle involved and is not limited eitheras to the character of the groove or as to the number and the characterof the layers constituting the backing.

What I claim is:

1. In combination in a mirror, 2. glass plate provided in its peripherywith a groove, a silvering coating on the back of the plate, a flexiblemetal securing member in said groove, and a flexible metal fabricextending over said coating and anchored at its edges-to said flexiblemember.

2. In combination in a mirror, a glass plate. provided in its peripheryWith a groove, a silvering coating on the back of the plate, a flexiblemetal fabric extending over such coating and over the grooved edge ofthe plate and a Wire lying in the groove over the edge of the fabric andclamping it in such groove.

In combination in a mirror, a glass plate provided in its periphery Witha groove, a silvering coating on the back of the plate, a flexible metalfabric extending over such coating and over the grooved edge of theplate, and a Wire lying in the groove over the edge of the fabric andclamping it in such groove, the extreme marginal portion of said fabricbeing folded back over the Wire.

l. In combination in a mirror, a glass plate provided in its peripherywith a groove, a silvering coating on the back of the plate, anelectrically deposited protecting coating extending over the silveringcoating, a flexible metal securing member in said groove, and a flexiblemetal fabric extending over said protecting coating and anchored at itsedges to said flexible member.

5. In combination in a mirror, a glass In testimony whereof, I havehereunto subscribed by name this 27th day of September, 1921.

WILLIAM H. TAYLOR.

lVitness F. H. MoNUTr.

